For improvement of safety and operability, some car navigation apparatuses employ a human-machine interface (HMI) that allows a user to input a facility name or the like by uttering word or words (speech). To implement the HMI, the car navigation apparatus is equipped with a speech recognition apparatus for recognizing the user-uttered speech (cf. JP-H9-114487A).
When the user inputs a name of facility etc. by his or her speech, the user's speech is recognized by the speech recognition apparatus. In this case, erroneous recognition can occur for the following reasons. When the user utters a name of facility etc. that is not registered in a database for speech recognition, the speech recognition of the name of facility etc. is unsuccessfully performed, and the erroneous recognition occurs.
In response to the erroneous recognition, the user may consider that his or her style of speaking is incorrect, or that the speech recognition apparatus has low recognition accuracy. Then, the user may try to utter the name of an input-target facility with different intonation with hope for successful speech recognition. In this case, since the speech recognition apparatus continues to perform the erroneous recognition, the user may give up using the speech recognition apparatus or may get a bad impression of the speech recognition apparatus.
In the case of the above kind of erroneous recognition, if the user speaks an input-target facility by calling it by another name (e.g., official name), the speech recognition may be successfully performed. This is because another name of the recognition-desired facility is registered in the database in many cases. However, in the case of the erroneous recognition, the user may get frustrated with the failure of the speech recognition and the user cannot take appropriate measures such as calling the facility by another name. This is experimentally shown.